Roman Numeral Converter
Convert whole numbers to Roman numerals, or Roman numerals back to numbers, instantly in your browser.
How to use the Roman Numeral Converter
- Choose Number to Roman numeral, or Roman numeral to Number.
- Enter a whole number from 1 to 3999, or a Roman numeral such as MCMXCIV.
- Click Run to see the conversion.
How the Roman Numeral Converter works
Roman numerals use seven letters: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500 and M = 1,000. Values are usually written largest to smallest and added together, but a smaller numeral placed before a larger one is subtracted: IV = 4, IX = 9, XL = 40, XC = 90, CD = 400 and CM = 900.
To convert a number, the tool repeatedly takes the largest value that fits (including those subtractive pairs). 1994 becomes M + CM + XC + IV = MCMXCIV. Standard notation tops out at 3,999 (MMMCMXCIX) because there is no single symbol for 5,000.
Frequently asked questions
- Is this Roman numeral converter free?
- Yes. Convert Roman numerals at no cost, with no account required.
- What numbers are supported?
- Whole numbers from 1 to 3999, the traditional range for standard Roman numerals.